The naphthol derivatives is the cheapest among condensed aromatic compounds which form a conjugated polyene system and has absorption in the electron band, and is easily used as raw materials for synthesis. Therefore, it has hitherto been used as various peculiar compounds, particularly raw materials such as dyes, pigments, photosensitive materials and the like.
As the naphthol derivatives like this, for example, there have been known 2-hydroxy-3-phenylaminocarbonylnaphthalene or 2-hydroxy-6-phenylaminocarbonylnaphthalene wherein a substituent is introduced at the 3-position or 6-position of 2-hydroxynaphthalene, and those wherein an alkyl or alkoxy group is added to these phenyl groups.
But as the naphthalene derivative which has substituents at both the 3-position and 6-position of 2-hydroxynaphthalene, 2-hydroxy-3,6-dihydroxycarbonylnaphthalene is merely known.
An object of the present invention is to provide novel derivatives of 3,6-di-substituted-2-hydroxynaphthalene, particularly 2-hydroxy-3,6-dihydroxycarbonylnaphthalene, which is useful as raw materials for synthesis, and a process for synthesizing the same.